From 7f24f8d34afa5c28a4794add18458bd451747ba3 Mon Sep 17 00:00:00 2001
From: Dmitriy Rabotyagov <dmitriy.rabotyagov@citynetwork.eu>
Date: Fri, 11 Sep 2020 15:24:14 +0300
Subject: [PATCH] Define condition for the first play host one time

We use the same condition, which defines against what host some "service"
tasks should run against, several times. It's hard to keep it the same
across the role and ansible spending additional resources to evaluate
it each time, so it's simpler and better for the maintenance to set
a boolean variable which will say for all tasks, that we want to run
only against signle host, if they should run or not now.

Change-Id: Ibdb078d39b3189c844aed14aa1ae74cb2ce97600
---
 tasks/cinder_post_install.yml |  2 +-
 tasks/main.yml                | 17 +++++------------
 vars/main.yml                 |  2 ++
 3 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/tasks/cinder_post_install.yml b/tasks/cinder_post_install.yml
index 2061ed80..dc510714 100644
--- a/tasks/cinder_post_install.yml
+++ b/tasks/cinder_post_install.yml
@@ -84,7 +84,7 @@
     flat: yes
   changed_when: false
   with_items: "{{ cinder_core_files }}"
-  run_once: true
+  when: _cinder_is_first_play_host
 
 - name: Copy common config
   config_template:
diff --git a/tasks/main.yml b/tasks/main.yml
index 8088430d..a19c4ac3 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -42,8 +42,7 @@
 
 - import_tasks: db_setup.yml
   when:
-    - "cinder_services['cinder-api']['group'] in group_names"
-    - "inventory_hostname == ((groups[cinder_services['cinder-api']['group']] | intersect(ansible_play_hosts)) | list)[0]"
+    - _cinder_is_first_play_host
   vars:
     _oslodb_setup_host: "{{ cinder_db_setup_host }}"
     _oslodb_databases:
@@ -57,8 +56,7 @@
 
 - import_tasks: mq_setup.yml
   when:
-    - "cinder_services['cinder-api']['group'] in group_names"
-    - "inventory_hostname == ((groups[cinder_services['cinder-api']['group']]| intersect(ansible_play_hosts)) | list)[0]"
+    - _cinder_is_first_play_host
   vars:
     _oslomsg_rpc_setup_host: "{{ cinder_oslomsg_rpc_setup_host }}"
     _oslomsg_rpc_userid: "{{ cinder_oslomsg_rpc_userid }}"
@@ -129,9 +127,7 @@
 
 - import_tasks: cinder_db_sync.yml
   when:
-    - "groups['cinder_api'] | length > 0"
-    - "cinder_services['cinder-api']['group'] in group_names"
-    - "inventory_hostname == ((groups['cinder_api'] | intersect(ansible_play_hosts)) | list)[0]"
+    - _cinder_is_first_play_host
   tags:
     - cinder-config
 
@@ -160,9 +156,7 @@
         password: "{{ cinder_service_password }}"
         role: "{{ cinder_service_role_name }}"
   when:
-    - "groups['cinder_api'] | length > 0"
-    - "cinder_services['cinder-api']['group'] in group_names"
-    - "inventory_hostname == ((groups['cinder_api'] | intersect(ansible_play_hosts)) | list)[0]"
+    - "_cinder_is_first_play_host"
   tags:
     - cinder-config
 
@@ -200,7 +194,6 @@
 - import_tasks: cinder_backends.yml
   when:
     - "groups[cinder_services['cinder-volume']['group']] | length > 0"
-    - "cinder_services['cinder-api']['group'] in group_names"
-    - "inventory_hostname == ((groups[cinder_services['cinder-api']['group']] | intersect(ansible_play_hosts)) | list)[-1]"
+    - "_cinder_is_first_play_host"
   tags:
     - cinder-config
diff --git a/vars/main.yml b/vars/main.yml
index b4581149..f8f23919 100644
--- a/vars/main.yml
+++ b/vars/main.yml
@@ -13,6 +13,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+_cinder_is_first_play_host: "{{ (cinder_services['cinder-api']['group'] in group_names and inventory_hostname == (groups[cinder_services['cinder-api']['group']] | intersect(ansible_play_hosts)) | first) | bool }}"
+
 _cinder_rootwrap_conf_overrides:
   DEFAULT:
     filters_path: "/etc/cinder/rootwrap.d,/usr/share/cinder/rootwrap"